Based on a V-shaped In(III) metal–organic framework (MOF): Design, synthesis and characterization of diverse physical and chemical properties

Abstract

The novel coordination polymer {[In3(OH)2L2(H2O)2]·H3O}n (1) was obtained by the hydrothermal reactions of InCl3 with a V-shaped multi-carboxylate ligand, 3,3′,4,4′-oxidiphthalic acid (H4OA), and an N-donor ligand (4,4′-bipyridine). Polymer 1 was characterized by elemental analysis, IR spectroscopy, UV–Vis spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis, photoluminescent (PL) spectra and surface photovoltage spectra. Various properties of H4OA and the polymer 1 were studied in the solid state and liquid state at room temperature. The single crystal X-ray diffraction analysis revealed that the coordination polymer possessed a new fascinating 3D network framework with evenly arranged pores, and the uncoordinated 4,4′-bipy molecules are embedded the robust 3D porous structure. This encouraged us to realize the influence of the N-donor ligand on the structure of the polymer. The metal–organic framework structural analysis revealed that the flexible multi-carboxylate and N-donor auxiliary ligands are effective building blocks in constructing coordination polymers with visually beautiful architectures. It provides a possibility for us to further study the multi-carboxylate OA4− ligand, which may adopt varied coordination modes in the formation of polymers. In the meantime we have conducted a test on malachite green dye adsorption and have obtained some good results, which is promising for application of polymer 1 in the field of water pollution treatment.